Linear motor system

Patent metadata

Field	Value
Publication number	US-9379649-B2
Application number	US-201414224071-A
Country	US
Kind code	B2
Filing date	Mar 25, 2014
Priority date	Aug 2, 2013
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A linear motor system includes a stator, a mover, and a controller. The stator includes a plurality of armature coil units arranged so as to be spaced apart from one another at certain intervals. The mover includes a permanent magnet. The controller is configured to sequentially select, as a power-feeding target, an armature coil unit opposing the mover from among the plurality of armature coil units, perform, for the power-feeding target, computation for power-feeding control on the basis of a speed command, and sequentially feed power to the armature coil unit. The controller includes a power-feeding-switching compensation function of performing switching compensation when the power-feeding target is switched to a next armature coil unit.

First claim

What is claimed is:

1. A linear motor system comprising:
a stator including a plurality of armature coil units linearly arranged so as to be spaced apart from one another at certain intervals;
a mover arranged so as to oppose the stator and including a permanent magnet; and
a controller configured to
sequentially select an armature coil unit opposing the mover from among the plurality of armature coil units, the selected armature coil unit serving as a power-feeding target,
perform, for the power-feeding target, computation for power-feeding control on the basis of a speed command, and
sequentially feed power to the armature coil unit serving as the power-feeding target in accordance with a result of the computation so as to drive the mover, wherein

the controller includes
a power-feeding-switching compensation function of performing, when the power-feeding target is switched to a next armature coil unit, switching compensation related to power-feeding control performed on the next armature coil unit.

2. The linear motor system according to claim 1 , wherein
the controller includes
a first controller section, and
a plurality of second controller sections each provided for a corresponding one of the plurality of armature coil units,

the first controller section includes
a speed command output unit configured to output a speed command to the second controller sections, and
a selection unit configured to sequentially select a second controller section corresponding to the armature coil unit opposing the mover from among the plurality of second controller sections, the selected second controller section serving as a target power-feeding controller, and

the plurality of second controller sections each include
a power-feeding control unit configured to perform, in a case where the second controller section is selected as the target power-feeding controller, computation for power-feeding control on the basis of the speed command output from the first controller section and to feed power to the corresponding armature coil unit in accordance with a result of the computation, and
a power-feeding-switching compensation unit configured to perform, when the power-feeding control unit performs the computation for power-feeding control, the switching compensation related to the power-feeding control performed by the power-feeding control unit.

3. The linear motor system according to claim 2 , further comprising
a position sensor configured to detect a position of the mover, wherein
the selection unit is configured to select, as the target power-feeding controller, the second controller section corresponding to the armature coil unit opposing the mover on the basis of a position detection signal output by the position sensor.

4. The linear motor system according to claim 3 , wherein
a region in which the plurality of armature coil units are arranged is divided into a positioning region and a transfer region,
the second controller section corresponding to the armature coil unit arranged in the positioning region is configured to perform position-based control using the position detection signal output by the position sensor, and
the second controller section corresponding to the armature coil unit arranged in the transfer region is configured to perform sensor-free control without using the position detection signal.

5. The linear motor system according to claim 3 , wherein
the mover includes a linear scale, and
the position sensor is a scale detection head included in the armature coil unit and configured to detect the linear scale so as to detect the position of the mover.

6. The linear motor system according to claim 2 , wherein
the plurality of second controller sections are connected to the first controller section via a communication connection so as to be connected to one another via the communication connection, and
the power-feeding-switching compensation unit of the second controller section presently selected as the target power-feeding controller is configured to perform the switching compensation on the basis of a state of power-feeding control performed by the second controller section selected as the target power-feeding controller immediately before the present target power-feeding controller.

7. The linear motor system according to claim 6 , wherein
the power-feeding control unit includes
a speed control unit configured to generate a torque command by using a speed integral value which is an integral of a deviation between the speed command and a speed of the mover, and

the power-feeding-switching compensation unit is configured to perform the switching compensation by setting a speed integral value held by the second controller section selected as the target power-feeding controller immediately before the present target power-feeding controller, as a speed integral value to be used by the speed control unit.

8. The linear motor system according to claim 6 , wherein
the power-feeding control unit includes
an estimation unit configured to compute an estimated phase and an estimated speed of the mover, and

the power-feeding-switching compensation unit is configured to perform the switching compensation by setting an estimated phase and an estimated speed obtained by the second controller section selected as the target power-feeding controller immediately before the present target power-feeding controller, as an estimated phase and an estimated speed to be used by the estimation unit.

9. The linear motor system according to claim 6 , wherein
the power-feeding control unit includes
a current control unit configured to control a current fed to the corresponding armature coil unit, in accordance with a torque command based on the speed command, and

the power-feeding-switching compensation unit is configured to perform the switching compensation by multiplying the torque command to be input to the current control unit by a torque ratio determined in accordance with a positional relationship between the mover and the second controller section selected as the target power-feeding controller immediately before the present target power-feeding controller.

10. A linear motor system comprising:
a stator including a plurality of armature coil units linearly arranged so as to be spaced apart from one another at certain intervals;
a mover arranged so as to oppose the stator and including a permanent magnet; and
controller means for
sequentially selecting an armature coil unit opposing the mover from among the plurality of armature coil units, the selected armature coil unit serving as a power-feeding target,
performing, for the power-feeding target, computation for power-feeding control on the basis of a speed command, and
sequentially feeding power to the armature coil unit serving as the power-feeding target in accordance with a result of the computation so as to drive the mover,

wherein
the controller means includes
a power-feeding-switching compensation function of performing, when the power-feeding target is switched to a next armature coil unit, switching compensation related to power-feeding control performed on the next armature coil unit.

11. The linear motor system according to claim 10 , wherein
the controller means includes
a first controller section, and
a plurality of second controller sections each provided for a corresponding one of the plurality of armature coil units,

the first controller section includes
speed command output means for outputting a speed command to the second controller sections, and
selection means for sequentially selecting a second controller section corresponding to the armature coil

Assignees

• Yaskawa Denki Seisakusho Kk

Inventors

• Takase Yoshiyasu
• Morimoto Shinya
• Shikayama Toru
• Koga Minoru
• Umeda Nobuhiro

Classifications

• H02P6/006 Primary

  Controlling linear motors · CPC title

• H02P23/22

  Controlling the speed digitally using a reference oscillator, a speed proportional pulse rate feedback and a digital comparator · CPC title

• H02P25/06

  Linear motors · CPC title